The transmission management system uses both
analogue and digital signals, to control the
operation of the transmission. Digital signals are
processed by the TCM to and from the vehicle
multiplex network. Other input/output analogue
signals are hardwired to the TCM. This
information is used primarily by the TCM to
decide which shift program to implement, which
gear to select and for shift energy management.
If a fault occurs, the TCM will take default action
and inform the driver via the Message Centre and
amber warning light.
The vehicle harness connector for the TCM is an
88-way latching connector. The TCM is wired to
the electrical pressure regulators/solenoids, oil
temperature sensor and shaft speed sensors in
the transmission casing.
When sport mode is selected by the driver using
the mode switch, the sport pattern is only
activated when a set cornering force is achieved,
or the kickdown switch is pressed. The vehicle
speed and the difference in speeds between the
two front wheels is used to calculate the amount
of cornering force.
Torque Convertor Lock-up
The torque convertor lock-up clutch is engaged
as a function of throttle position, output speed,
oil temperature, gear shift and shift program.
Lockup is possible in 2nd, 3rd, 4th and 5th gears
but is usually restricted to 4th and 5th gears.
During a gear shift the TCM controls the amount
of slip of the lock-up clutch to enhance shift
When the engine coolant or transmission oil
temperature exceeds set thresholds a hot mode
program is selected which locks the torque
convertor clutch, minimising the amount of heat
entering the engine cooling system from the